Your shoulder aches when you reach for a high shelf. Your hip burns when you roll onto it at night. Your elbow swells into a soft lump after a week of leaning on a desk. Three joints, one culprit: an irritated bursa.
Bursae are thin, fluid-filled sacs sitting between bone and the soft tissue that slides over it. Inflamed, they thicken and swell, and that inflammation is bursitis. It is a common reason adults arrive in primary care with joint pain that turns out not to be arthritis. Most cases settle within weeks; a small minority are urgent. Telling them apart is the point of this guide.
What is bursitis?
The adult body carries roughly 150 bursae, and new ones form wherever friction repeats. Each is a flattened pouch lined with synovial membrane, the tissue that also lines a joint, holding a film of slippery fluid. The job is mechanical: let a tendon glide across a bony ridge without shredding itself. When the pouch inflames, the lining thickens, the sac balloons, and the structure designed to eliminate friction becomes the source of the pain.
Two patterns exist. Non-septic bursitis, also called aseptic, is inflammation without infection, driven by repetitive loading, sustained pressure, or inflammatory disease. Septic bursitis means bacteria have colonized the sac, usually Staphylococcus aureus entering through broken skin. Superficial bursae at the elbow tip and kneecap swell visibly and are the ones that get infected; deep bursae at the shoulder and hip hurt without any visible lump.
Symptoms and warning signs
The core complaint is localized pain that worsens with movement and pressure. Most people can point to it with one fingertip, which already separates bursitis from the broader ache of arthritis.
- Pain that spikes when the tendon works against resistance: reaching overhead, climbing stairs, kneeling.
- Tenderness over one bony point rather than across the joint line.
- Soft, squishy swelling at superficial sites, and none at deep ones.
- Night pain when lying on the affected side, often the symptom that prompts a visit.
Symptoms building over weeks point to mechanical overload; symptoms arriving within hours, especially with fever, belong in a different category. When pain has simmered without improving, your clinician may order a C-reactive protein test that measures systemic inflammation.
How to tell septic bursitis from ordinary inflammation
This is why a swollen elbow should never simply be iced and forgotten. Infection is common in superficial bursitis and, unlike the aseptic form, does not resolve on its own.
- Fever or chills, uncommon in aseptic bursitis and frequent in septic cases.
- Skin that feels hot rather than warm, with redness spreading beyond the swelling.
- Any break in the skin over the bursa: an abrasion, cut, or insect bite.
- Pain at rest, out of proportion to the swelling, with onset over days not weeks.
- Diabetes, immune suppression, or steroid use, which raise risk and mute the classic signs.
Aspiration settles it: a needle draws fluid for Gram stain and culture. Checking neutrophil counts and what a sharp rise indicates signals early that bacteria rather than friction are driving the swelling.
Where bursitis happens: the main sites
Bursitis is one mechanism appearing in predictable places, each with its own signature.
| Site | Typical trigger | What it feels like |
|---|---|---|
| Shoulder (subacromial) | Overhead work, swimming, weak rotator cuff | Painful arc partway through lifting the arm; deep ache down the outer upper arm |
| Hip (greater trochanteric) | Long walks or runs, weak hip abductors, side sleeping | Burning over the bony point on the outer hip; sharp on stairs; intense at night |
| Knee, front (prepatellar) | Prolonged kneeling on hard floors | Visible, squashy swelling on the kneecap; bending limited by bulk |
| Elbow (olecranon) | Leaning on desks or armrests, a knock to the elbow tip | Soft, mobile lump at the elbow point; painless when aseptic, hot and red when infected |
Hip bursitis deserves an extra word. What was long called trochanteric bursitis is now usually described as greater trochanteric pain syndrome, since imaging shows gluteal tendon degeneration is often the primary problem and bursal inflammation a consequence. That explains why rest and injections alone disappoint, and why loading the hip abductors is now the cornerstone of care.
Causes and risk factors
Three routes lead to an inflamed bursa: repetition, sustained pressure, and a systemic inflammatory driver.
- Occupation and hobby. Carpet layers, roofers, and plumbers top the list, alongside swimmers and runners.
- Age. Tendons lose elasticity from midlife on, so the same workload creates more friction at fifty-five than twenty-five.
- Biomechanics. Weak hip abductors, poor scapular control, and leg-length difference shift load onto structures not built for it.
- Body weight, and trauma such as a fall onto the elbow.
- Anyone managing rheumatoid arthritis and the joints it attacks first carries a raised baseline risk.
- Diabetes and immune suppression, which raise both the likelihood and severity of septic bursitis.
Crystal disease deserves mention. Uric acid crystals deposit in a bursa exactly as they do in a joint, producing a hot, tender swelling that mimics infection. Getting it wrong means unnecessary antibiotics or a missed infection, so before assuming overuse it is worth understanding gout and the crystal attacks that define it.
How bursitis is diagnosed
Diagnosis starts with the story and the examination: what changed before the pain began, tenderness over bony landmarks, and resisted movements that reproduce the symptom. Point tenderness with preserved passive motion is the classic pattern.
Imaging is selective. Ultrasound is the workhorse, showing fluid inside the bursa in real time and guiding a needle into the sac. MRI is reserved for unclear cases, suspected tendon tears, or deep infection. Where infection is possible, aspiration is decisive: aseptic fluid is clear, infected fluid cloudy.
The blood tests that matter
No blood test diagnoses bursitis. Bloodwork answers the questions that change management: is this infected, inflammatory, or crystal-driven?
A first-line panel usually includes a complete blood count that maps your white cell populations. A raised count with neutrophil predominance shifts suspicion toward infection, though a normal count does not rule it out in older or immunosuppressed patients. C-reactive protein rises within hours and falls once inflammation settles, which makes it useful for tracking antibiotics. Many clinicians pair it with the erythrocyte sedimentation rate and its reference ranges, a slower marker spanning weeks.
Where the presentation is atypical, further tests earn their place. Reviewing uric acid levels and what pushes them upward helps separate a crystal flare from an overuse injury, although uric acid can read normal during an acute attack. Rheumatoid factor matters when several joints are involved, and procalcitonin is sometimes added in hospital.
Treatment options
Treatment splits along the septic and non-septic line, so establishing which you have comes first. For non-septic bursitis, phase one lowers the load without shutting the limb down. Relative rest means avoiding the aggravating movement while still using the joint, since immobilization causes stiffness and weakness that outlast the original problem. Padding matters more than people expect: kneepads for floor work, an elbow sleeve at a desk, a pillow between the knees for side sleepers.
Structured exercise delivers the durable gains. A physical therapist corrects the mechanics that caused the overload, then progressively loads the tendon and muscle supporting the bursa. Progress is measured in weeks to months, and early exercise sometimes feels worse first.
Ultrasound-guided corticosteroid injection can break a pain cycle blocking rehabilitation, but its value is time-limited and repeated injections risk tendon weakening. Injection is avoided where infection is possible. Aspiration helps large, tense swellings, though fluid often reaccumulates. Shockwave therapy and platelet-rich plasma have promising but not decisive evidence.
Septic bursitis follows a different path: aspiration for culture, then antibiotics targeting staphylococci and streptococci. Mild cases are managed orally; severe ones need intravenous treatment and sometimes drainage. Untreated soft-tissue infection can escalate, so it is worth learning to recognize sepsis and the warning signs that precede it.
Prevention and daily management
- Increase training volume gradually. Rises above roughly ten percent per week are where overuse injuries cluster.
- Warm up before repetitive work, not just sport, and change position every half hour.
- Pad any joint that meets a hard surface.
- Build strength in the muscles controlling the joint: hip abductors for the hip, rotator cuff for the shoulder, quadriceps for the knee.
- Clean and cover any break in the skin over the elbow or kneecap.
During a flare, use a traffic light. Green: no pain, continue freely. Amber: mild discomfort settling within a day, modify and keep going. Red: sharp pain or next-day soreness, pause and resume at reduced load.
Living with bursitis: outlook
The outlook is good. Most non-septic cases improve substantially within two to six weeks with activity modification, and the great majority resolve within a few months.
The frustrating cases are chronic ones at the hip and shoulder, grumbling on for six months or more. These rarely reflect persistent inflammation; they reflect an underlying tendon problem or a return to activity before the supporting muscles recovered, and the answer is a longer loading program rather than more rest. Older adults with lateral hip pain frequently also have osteoarthritis and the cartilage wear that defines it, and treating only one of the two leaves the person still in pain.
Latest scientific advances
A systematic review and meta-analysis pooled six randomized trials covering 733 patients with greater trochanteric pain syndrome, the modern name for hip bursitis, comparing supervised exercise against inactive controls, corticosteroid injection, and shockwave therapy. In the long term, exercise slightly reduced hip pain and disease severity while improving self-reported function, with no serious adverse events in any trial. Against corticosteroid injection, exercise produced a better long-term global rating of change, meaning more patients felt meaningfully better months later (Kjeldsen et al., 2024). What this means for you: an injection may feel like the faster fix, but supervised exercise is what holds up at one year, so ask for physical therapy early.
A later systematic review restricted itself to high-quality trials at low risk of bias and used standardized mean differences, a statistic where about 0.8 counts as a large effect and 0.2 as a small one. Exercise combined with patient education showed a medium effect on pain at 0.95 (95% confidence interval 0.58 to 1.33) and on function at 0.91 (0.53 to 1.28) short term. Corticosteroid injection produced only a small effect on pain at 0.51 (0.16 to 0.86), and platelet-rich plasma beat corticosteroid for short-term function (Bremer et al., 2025). What this means for you: education about what to avoid, delivered alongside exercise, is not filler; it was part of the package that beat injections.
On the shoulder side, a Bayesian network meta-analysis, a method that ranks treatments even when never compared directly, examined seven exercise types for rotator cuff-related shoulder pain, a category that includes subacromial bursitis. The pain network drew on 15 studies covering 913 participants, the function network on 16 studies covering 947. Concentric strengthening, in which the muscle shortens as it contracts, ranked first for function and had the highest probability of ranking first for pain, while eccentric and traditional strengthening beat scapula-focused exercise (Zhang et al., 2025). What this means for you: if your shoulder program is mostly posture drills, ask whether progressive resistance work should be added.
Myths and facts
- Myth: complete rest is the cure. Fact: prolonged immobilization creates stiffness that prolongs the problem.
- Myth: a cortisone shot fixes it. Fact: it reduces short-term pain, but trials show exercise does better long term.
- Myth: painless elbow swelling is harmless. Fact: redness, heat, or fever changes that entirely.
- Myth: bursitis only affects older people. Fact: prepatellar bursitis is common in young tradespeople.
Glossary
| Term | What it means |
|---|---|
| Bursa | A small fluid-filled sac reducing friction between bone and the tissue moving over it |
| Aseptic bursitis | Bursal inflammation without infection, from repetitive load, pressure, or disease |
| Septic bursitis | Bacterial infection inside a bursa, usually via broken skin |
| Aspiration | Withdrawing bursal fluid with a needle to relieve pressure and test the sample |
| Subacromial | Beneath the acromion, the bony shelf atop the shoulder blade |
| Greater trochanter | The bony prominence on the outer upper thigh bone; the landmark for hip bursitis |
| Olecranon | The pointed tip of the elbow; prepatellar is its equivalent in front of the kneecap |
| Tendinopathy | Tendon degeneration from overload, often found alongside chronic bursitis |
Frequently asked questions
What causes bursitis?
Three mechanisms account for most cases. Repetitive movement is commonest: overhead reaching, running, or any task repeated thousands of times in a joint not conditioned for it. Sustained pressure is second, which is why kneeling trades develop prepatellar bursitis and desk workers develop olecranon bursitis. Third is a systemic driver, where rheumatoid arthritis or gout inflames the bursa from within. Infection is a separate route entirely.
How long does bursitis last?
Most non-septic cases improve noticeably within two to six weeks once the aggravating activity is modified, and the majority resolve within a few months. Superficial bursitis at the elbow or knee settles faster than deep bursitis at the hip or shoulder, where an underlying tendon problem needs months of strengthening. Septic bursitis responds to antibiotics within days but needs a full two- to three-week course.
How do you treat bursitis at home?
Start by identifying and modifying the specific movement that hurts, while continuing to use the limb normally otherwise. Apply ice for fifteen to twenty minutes several times daily for the first few days. Add padding wherever the joint meets a hard surface: kneepads, an elbow sleeve, a pillow between the knees at night. Then begin gentle movement and progress to strengthening. Seek care if fever develops.
What are the symptoms of hip bursitis?
The hallmark is pain over the bony point on the outer hip, usually burning or aching rather than sharp. It worsens when lying on that side, which makes night pain the complaint most people mention first. Climbing stairs, crossing the legs, and getting out of a car all reproduce it. Pain can radiate down the outer thigh, sometimes prompting a mistaken diagnosis of a trapped nerve.
Is bursitis serious?
Ordinary non-septic bursitis is painful and disruptive but not dangerous, and it does not damage the joint itself. Septic bursitis is genuinely serious: an untreated bursal infection can spread into surrounding skin and soft tissue and occasionally into the bloodstream. That is why fever, spreading redness, heat, or onset over a day or two justify same-day assessment rather than watchful waiting.
What exercises help bursitis?
The right exercises depend on the site, and progressive strengthening matters more than stretching. For lateral hip pain, isometric holds for the hip abductors followed by side-lying leg raises, bridges, and step-downs address the muscles controlling the pelvis. For the shoulder, progressive resistance work for the rotator cuff is supported by recent trial evidence, outperforming posture drills. Start below the level that provokes pain.
Sources
- National Library of Medicine — Bursitis — MedlinePlus, 2024 — medlineplus.gov
- Mayo Clinic — Bursitis: Symptoms and Causes — Mayo Foundation, 2025 — mayoclinic.org
- Cleveland Clinic — Bursitis — Cleveland Clinic Health Library, 2024 — my.clevelandclinic.org
- AAOS — Hip Bursitis — OrthoInfo, 2024 — orthoinfo.aaos.org
- AAOS — Elbow (Olecranon) Bursitis — OrthoInfo, 2024 — orthoinfo.aaos.org
- Kjeldsen T, et al. — Exercise vs other conservative treatments in Greater Trochanteric Pain Syndrome — Physiotherapy, 2024 — doi.org
- Bremer T, et al. — The efficacy of gluteal tendinopathy treatments — Clinical Rehabilitation, 2025 — doi.org
- Zhang W, et al. — Effects of seven types of exercise for rotator cuff-related shoulder pain — Journal of Orthopaedic Surgery and Research, 2025 — doi.org
Further reading
- If your joint pain moves between sites or affects both sides, it is worth reading arthritis and the many forms it takes.
- Anyone whose clinician suspects an inflammatory cause should review rheumatoid factor and what a positive result means.
- When antibiotics are considered, your team may explain procalcitonin and its role in identifying bacterial illness.
- Adults who have cut back on activity should also consider osteoporosis and the bone loss that follows inactivity.
- If a fall came before your swelling, it helps to recognize bone fractures and the signs that point toward them.
Understand your lab results with BloodSense
Bursitis is diagnosed at the bedside, not the laboratory, but the tests around it decide what happens next. A white cell count and neutrophil percentage help judge whether a swollen elbow is infected. C-reactive protein tracks how fast inflammation falls once treatment starts, uric acid changes the odds of a crystal cause, and rheumatoid factor points toward inflammatory disease.
Those numbers arrive as values and reference ranges that rarely explain themselves. BloodSense reads your report, puts each marker in context, and tells you which results are reassuring, which are drifting, and which to raise with your clinician.
